Patent Grant
7866383
This invention relates, in general, to controlling the production of particulate materials from a subterranean formation and, in particular, to a sand control screen assembly having radially extendable filter members that are operable to contact the formation upon actuation.
Without limiting the scope of the present invention, its background is described with reference to the production of hydrocarbons through a wellbore traversing an unconsolidated or loosely consolidated formation, as an example.
It is well known in the subterranean well drilling and completion art that particulate materials such as sand may be produced during the production of hydrocarbons from a well traversing an unconsolidated or loosely consolidated subterranean formation. Numerous problems may occur as a result of the production of such particulate materials. For example, the particulate materials cause abrasive wear to components within the well, such as tubing, flow control devices and safety devices. In addition, the particulate materials may partially or fully clog the well creating the need for an expensive workover. Also, if the particulate materials are produced to the surface, they must be removed from the hydrocarbon fluids by processing equipment at the surface.
One method for preventing the production of such particulate materials is gravel packing the well adjacent the unconsolidated or loosely consolidated production interval. In a typical gravel pack completion, a sand control screen is lowered into the wellbore on a work string to a position proximate the desired production interval. A fluid slurry including a liquid carrier and a particulate material, such as gravel, is then pumped down the work string and into the well annulus formed between the sand control screen and the perforated well casing or open hole production zone.
The liquid carrier either flows into the formation, returns to the surface by flowing through the sand control screen or both. In either case, the gravel is deposited around the sand control screen to form a gravel pack, which is highly permeable to the flow of hydrocarbon fluids but blocks the flow of the particulate carried in the hydrocarbon fluids. As such, gravel packs can successfully prevent the problems associated with the production of particulate materials from the formation.
It has been found, however, that a complete gravel pack of the desired production interval is difficult to achieve particularly in extended or deviated wellbores including wellbores having long, horizontal production intervals. These incomplete packs are commonly a result of the liquid carrier entering a permeable portion of the production interval causing the gravel to dehydrate and form a sand bridge in the annulus. Thereafter, the sand bridge prevents the slurry from flowing to the remainder of the annulus which, in turn, prevents the placement of sufficient gravel in the remainder of the production interval.
In addition, it has been found that gravel packing is not feasible in certain open hole completions. Attempts have been made to use expandable metal sand control screens in such open hole completions. These expandable metal sand control screens are typically installed in the wellbore then radially expanded using a hydraulic swage or cone that passes through the interior of the screen or other metal forming techniques. In addition to filtering particulate materials out of the formation fluids, one benefit of these expandable sand control screens is the radial support they provide to the formation which helps prevent formation collapse. It has been found, however, that conventional expandable sand control screens do not contact the wall of the wellbore along their entire length as the wellbore profile is not uniform. More specifically, due to the process of drilling the wellbore and heterogeneity of the downhole strata, washouts or other irregularities commonly occur which result in certain locations within the wellbore having larger diameters than other areas or having non circular cross sections. Thus, when the expandable sand control screens are expanded, voids are created between the expandable sand control screens and the irregular areas of the wellbore, which has resulted in incomplete contact between the expandable sand control screens and the wellbore. In addition, with certain conventional expandable sand control screens, the threaded connections are not expandable which creates a very complex profile, at least a portion of which does not contact the wellbore. Further, when conventional expandable sand control screens are expanded, the radial strength of the expanded screens is drastically reduced resulting in little, if any, radial support to the borehole.
Therefore, a need has arisen for a sand control screen assembly that prevents the production of particulate materials from a well that traverses a hydrocarbon bearing subterranean formation without the need for performing a gravel packing operation. A need has also arisen for such a sand control screen assembly that provides radial support to the formation without the need for expanding metal tubulars. Further, a need has arisen for such a sand control screen assembly that is suitable for operation in long, horizontal, open hole completions.
The present invention disclosed herein comprises a sand control screen assembly that prevents the production of particulate materials from a well that traverses a hydrocarbon bearing subterranean formation or operates as an injection well. The sand control screen assembly of the present invention achieves this result without the need for performing a gravel packing operation. In addition, the sand control screen assembly of the present invention interventionlessly provides radial support to the formation without the need for expanding metal tubulars. Further, the sand control screen assembly of the present invention is suitable for operation in open hole completions in long, horizontal production intervals.
In one aspect, the present invention is directed to a sand control screen assembly that is operable to be positioned within a wellbore. The sand control screen assembly includes a base pipe having at least one opening in a sidewall portion thereof and an internal flow path. A plurality of radially extendable filter members are each operably associated with at least one of the openings of the base pipe. The radially extendable filter members have a circumferential dimension that is less than a longitudinal dimension thereof. The radially extendable filter members also have a radially retracted running configuration and a radially extended operating configuration, in which, the radially extendable filter members are preferably in close proximity to or contact with the wellbore.
In one embodiment, a swellable material layer is disposed between the base pipe and at least a portion of the radially extendable filter members such that, in response to contact with an activating fluid, radial expansion of the swellable material layer causes the radially extendable filter members to operate from their running configuration to their operating configuration. In this embodiment, the activating fluid may be a hydrocarbon fluid, water, gas or the like.
In one embodiment, the radially extendable filter members include a cylinder that is coupled to the base pipe and a radially telescoping piston slidably received within the cylinder. In certain embodiments, the radially extendable filter members include a filter retainer and filter medium. In other embodiments, the radially extendable filter members include a perforated tubular. The filter medium associated with the radially extendable filter members may be any one or more of a single layer mesh screen, a multiple layer mesh screen, a wire wrapped screen, a prepack screen, a ceramic screen, metallic or ceramic balls or beads the are sintered or unsintered, a fluid porous, particulate resistant sintered wire mesh screen and a fluid porous, particulate resistant diffusion bonded wire mesh screen.
In one embodiment, the ratio between the circumferential dimension and the longitudinal dimension of the radially extendable filter members is at least 1 to 2. In another embodiment, the ratio between the circumferential dimension and the longitudinal dimension of the radially extendable filter members is between about 1 to 2 and about 1 to 10. In a further embodiment, the ratio between the circumferential dimension and the longitudinal dimension of the radially extendable filter members is between about 1 to 10 and about 1 to 30.
In some embodiments, a fluid flow control device is operably associated with each of the radially extendable filter members. In other embodiments, a fluid flow control device may be operably associated with a plurality of the radially extendable filter members.
In another aspect, the present invention is directed to a sand control screen assembly that is operable to be positioned within a wellbore. The sand control screen assembly includes a base pipe having a plurality of openings in a sidewall portion thereof and an internal flow path. A plurality of radially extendable filter members are each operably associated with at least one of the openings of the base pipe. The radially extendable filter members have a circumferential dimension that is less than a longitudinal dimension thereof. A swellable material layer is disposed exteriorly of the base pipe, such that, in response to contact with an activating fluid, radial expansion of the swellable material layer causes at least a portion of the radially extendable filter members to be displaced toward and preferably in close proximity or contact with a surface of the wellbore.
In a further aspect, the present invention is directed to a method of installing a sand control screen assembly in a wellbore. The method includes running the sand control screen assembly to a target location within the wellbore, the sand control screen assembly including a plurality of radially extendable filter members each of which is operably associated with at least one opening of a base pipe, the radially extendable filter members having a circumferential dimension that is less than a longitudinal dimension thereof and operating the radially extendable filter members from a radially retracted running configuration to a radially extended operating configuration.
For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the present invention.
Referring initially to
Positioned within wellbore 12 and extending from the surface is a tubing string 22. Tubing string 22 provides a conduit for formation fluids to travel from formation 20 to the surface. Positioned within tubing string 22 is a plurality of sand control screen assemblies 24. The sand control screen assemblies 24 are shown in a running or unextended configuration.
Referring also to
Even though
In addition, even though
Referring to
In the illustrated embodiment and as best seen in
Referring additionally now to
One benefit provided by the sand control screen assemblies of the present invention is that in addition to providing a plurality of paths for formation fluids to enter internal flow path 44 and filtering particulate materials out of the formation fluids, the sand control screen assemblies of the present invention also provide support to the formation to prevent formation collapse. Compared with convention expandable metal sand control screens as discussed above, the sand control screen assemblies of the present invention provide improved contact with the formation as greater radial expansion is achievable and the swellable material layer is more compliant such that it is better able to conform to a nonuniform wellbore face. In a preferred implementation, the sand control screen assemblies of the present invention provide between about 500 psi and 2000 psi of collapse support to the wellbore. Those skilled in the art will recognize that the collapse support provided by the present invention can be optimized for a particular implementation though specific design features of the base pipe and the swellable material layer.
Various techniques may be used for contacting swellable material layer 48 with an appropriate activating fluid for causing swelling of swellable material layer 48. For example, the activating fluid may already be present in the well when sand control screen assembly 40 is installed in the well, in which case swellable material layer 48 preferably includes a mechanism for delaying the swelling of swellable material layer 48 such as an absorption delaying or preventing coating or membrane, swelling delayed material compositions or the like.
Alternatively, the activating fluid may be circulated through the well to swellable material layer 48 after sand control screen assembly 40 is installed in the well. As another alternative, the activating fluid may be produced into the wellbore from the formation surrounding the wellbore. Thus, it will be appreciated that any method may be used for causing swelling of swellable material layer 48 of sand control screen assembly 40 in keeping with the principles of the invention.
Swellable material layer 48 is formed from one or more materials that swell when contacted by an activation fluid such as an inorganic or organic fluid. For example, the material may be a polymer that swells multiple times its initial size upon activation by an activation fluid that stimulates the material to expand. In one embodiment, the swellable material is a material that swells upon contact with and/or absorption of a hydrocarbon, such as an oil or a gas. The hydrocarbon is absorbed into the swellable material such that the volume of the swellable material increases creating a radial expansion of the swellable material. Preferably, the swellable material will swell until its outer surface and radially extendable filter members 52 contact the formation face in an open hole completion or the casing wall in a cased wellbore. The swellable material accordingly provides the energy to radially extend radially extendable filter members 52 in contact with the formation.
Some exemplary swellable materials include elastic polymers, such as EPDM rubber, styrene butadiene, natural rubber, ethylene propylene monomer rubber, ethylene propylene diene monomer rubber, ethylene vinyl acetate rubber, hydrogenized acrylonitrile butadiene rubber, acrylonitrile butadiene rubber, isoprene rubber, chloroprene rubber and polynorbornene. These and other swellable materials swell in contact with and by absorption of hydrocarbons so that the swellable materials expand. In one embodiment, the rubber of the swellable materials may also have other materials dissolved in or in mechanical mixture therewith, such as fibers of cellulose. Additional options may be rubber in mechanical mixture with polyvinyl chloride, methyl methacrylate, acrylonitrile, ethylacetate or other polymers that expand in contact with oil.
In another embodiment, the swellable material is a material that swells upon contact with water. In this case, the swellable material may be a water-swellable polymer such as a water-swellable elastomer or water-swellable rubber. More specifically, the swellable material may be a water-swellable hydrophobic polymer or water-swellable hydrophobic copolymer and preferably a water-swellable hydrophobic porous copolymer. Other polymers useful in accordance with the present invention can be prepared from a variety of hydrophilic monomers and hydrophobically modified hydrophilic monomers. Examples of particularly suitable hydrophilic monomers which can be utilized include, but are not limited to, acrylamide, 2-acrylamido-2-methyl propane sulfonic acid, N,N-dimethylacrylamide, vinyl pyrrolidone, dimethylaminoethyl methacrylate, acrylic acid, trimethylammoniumethyl methacrylate chloride, dimethylaminopropylmethacrylamide, methacrylamide and hydroxyethyl acrylate.
A variety of hydrophobically modified hydrophilic monomers can also be utilized to form the polymers useful in accordance with this invention. Particularly suitable hydrophobically modified hydrophilic monomers include, but are not limited to, alkyl acrylates, alkyl methacrylates, alkyl acrylamides and alkyl methacrylamides wherein the alkyl radicals have from about 4 to about 22 carbon atoms, alkyl dimethylammoniumethyl methacrylate bromide, alkyl dimethylammoniumethyl methacrylate chloride and alkyl dimethylammoniumethyl methacrylate iodide wherein the alkyl radicals have from about 4 to about 22 carbon atoms and alkyl dimethylammonium-propylmethacrylamide bromide, alkyl dimethylammonium propylmethacrylamide chloride and alkyl dimethylammonium-propylmethacrylamide iodide wherein the alkyl groups have from about 4 to about 22 carbon atoms.
Polymers which are useful in accordance with the present invention can be prepared by polymerizing any one or more of the described hydrophilic monomers with any one or more of the described hydrophobically modified hydrophilic monomers. The polymerization reaction can be performed in various ways that are known to those skilled in the art, such as those described in U.S. Pat. No. 6,476,169 which is hereby incorporated by reference for all purposes.
Suitable polymers may have estimated molecular weights in the range of from about 100,000 to about 10,000,000 and preferably in the range of from about 250,000 to about 3,000,000 and may have mole ratios of the hydrophilic monomer(s) to the hydrophobically modified hydrophilic monomer(s) in the range of from about 99.98:0.02 to about 90:10.
Other polymers useful in accordance with the present invention include hydrophobically modified polymers, hydrophobically modified water-soluble polymers and hydrophobically modified copolymers thereof. Particularly suitable hydrophobically modified polymers include, but are not limited to, hydrophobically modified polydimethylaminoethyl methacrylate, hydrophobically modified polyacrylamide and hydrophobically modified copolymers of dimethylaminoethyl methacrylate and vinyl pyrollidone.
As another example, the swellable material may be a salt polymer such as polyacrylamide or modified crosslinked poly(meth)acrylate that has the tendency to attract water from salt water through osmosis wherein water flows from an area of low salt concentration, the formation water, to an area of high salt concentration, the salt polymer, across a semi permeable membrane, the interface between the polymer and the production fluids, that allows water molecules to pass therethrough but prevents the passage of dissolved salts therethrough.
In the illustrated embodiment, radially extendable filter members 52 have been designed to be compliant with the surface of the wellbore. Specifically, radially extendable filter members 52 have a relatively narrow circumferential dimension and a relatively extended longitudinal dimension, as best seen in the comparison of
In addition, extendable filter members 52 provide a relatively large interface contact area with the formation. Having this large interface contact area reduces the localized draw down associated with production into the wellbore as compared to fluid inlets having relatively small points of entry, thereby reducing the risk of coning of an unwanted fluid such as water or gas in an oil production operation. Having a relatively large interface contact area compared to the fluid discharge area of individual radially extendable filter members 52 or collections of radially extendable filter members 52 further reduces localized drawdown, as explained in greater detail below.
Even though radially extendable filter members 52 have been depicted as having a particular cross sectional shape, it should be understood by those skilled in the art that the radially extendable filter members of the present invention could alternatively have cross sections of different shapes including circles, such as radially extendable filter member 70 of
Even though radially extendable filter members 52 have been described as having a filter medium attached to a filter retainer, those skilled in the art will recognize that other types of radially extendable filter members could alternatively be used. For example, as best seen in
Additionally, even though radially extendable filter member 90 has been described as having tubular members in the shape of a “T”, those skilled in the art will recognize that other tubular configurations could alternatively be used and would be considered within the scope of the present invention. For example, as best seen in
Referring again to
In one embodiment, the outer layer of filter medium 60 may have the reactive substance impregnated therein. For example, the reactive substance may fill the voids in the outer layer of filter medium 60 during installation. Preferably, the reactive substance is degradable when exposed to a subterranean well environment. More preferably, the reactive substance degrades when exposed to water at an elevated temperature in a well. Most preferably, the reactive substance is provided as described in U.S. Pat. No. 7,036,587 which is hereby incorporated by reference for all purposes.
In certain embodiments, the reactive substance includes a degradable polymer. Suitable examples of degradable polymers that may be used in accordance with the present invention include polysaccharides such as dextran or cellulose, chitins, chitosans, proteins, aliphatic polyesters, poly(lactides), poly(glycolides), poly(ε-caprolactones), poly(anhydrides), poly(hydroxybutyrates), aliphatic polycarbonates, poly(orthoesters), poly(amino acids), poly(ethylene oxides), and polyphosphazenes. Of these suitable polymers, aliphatic polyesters such as poly(lactide) or poly(lactic acid) and polyanhydrides are preferred.
The reactive substance may degrade in the presence of a hydrated organic or inorganic compound solid, which may be included in sand control screen assembly 40, so that a source of water is available in the well when the screens are installed. Alternatively, another water source may be delivered to the reactive substance after sand control screen assembly 40 is conveyed into the well, such as by circulating the water source down to the well or formation water may be used as the water source.
Referring next to
Alternatively, depending upon the desired operation, fluid flow control device 150 may take a variety of other forms. For example, it may be desirable to temporarily prevent fluid flow through radially extendable filter member 148. In this case, fluid flow control device 150 may be a dissolvable, removable or shearable plug formed from sand, salt, wax, aluminum, zinc or the like or may be a pressure activated device such as burst disk. As another example, it may be desirable to prevent fluid loss into the formation during high pressure operations internal to the sand control screen assembly including radially extendable filter member 148, in which case, fluid flow control device 150 may be a one-way valve or a check valve. As yet another example, it may be desirable to control the type of fluid entering the sand control screen assembly including radially extendable filter member 148, in which case, fluid flow control device 150 may be a production control device such as a valve that closes responsive to contact with an undesired fluid, such as water. Such valves may be actuated by a swellable material including those discussed above, organic fibers, an osmotic cell or the like.
Referring next to
Disposed between base pipe 162 and sleeve 164 is a pair of fluid flow control devices 178, 180. As described above, depending upon the desired operation, fluid flow control devices 178, 180 may take a variety of forms including in any combination of dissolvable, removable or shearable plugs, a burst disk, a one-way valve, a check valve, a nozzle, a flow tube, an orifice or other flow restrictor, a valve that closes responsive to contact with an undesired fluid and the like. In this embodiment, production through multiple radially extendable filter members 174 is combined in the common annular chamber or manifold 182 defined between base pipe 162 and sleeve 164. This provides the benefit of a uniform draw down being applied across the entire length and circumference of sand control screen assembly 160. If it is desired to have unrestricted flow, in certain embodiments, sleeve 164 is removable by mechanical or chemical means.
Additionally or alternatively, a sliding sleeve (not pictured) may be operably associated with sleeve 164 and openings 166. The sliding sleeve may be disposed internally of sleeve 164 within internal flow path 168 or may preferably be disposed externally of sleeve 164 within annular chamber 182. The sliding sleeve may have an open position wherein fluid flow through openings 166 is allowed and a closed position wherein fluid flow though openings 166 is prevented. In addition, the position of the sliding sleeve may be infinitely variable such that the sliding sleeve may provide a choking function. The sliding sleeve may be operated mechanically, electrically, hydraulically or by other suitable means.
Referring to
Radially extendable filter members 198 each includes a cylinder 200 that is attached to base pipe 192 by threading, welding, friction fit or other suitable technique. Slidably positioned within cylinder 200 is a radially telescoping piston 202. Attached to the outer surface of piston 202 is a filter retainer 204. Filter retainer 204 supports an outer filter member 206. As illustrated, outer filter member 206 is a mechanical screening element such as a woven wire or fiber mesh. In addition, disposed within piston 202 is a second screening element 208 such as prepacked or resin coated sand, metallic or ceramic balls or beads that may be sintered or unsintered or the like. Radially extendable filter members 198 also include a fluid flow control device 210. In this embodiment that does not include a swellable material layer, pressure within internal flow path 194 of sand control screen assembly 190 is preferably used to shift radially extendable filter members 198 from their running position to their operating position, as best seen in
Referring to
Radially extendable filter members 228 each includes a cylinder 230 that is attached to base pipe 222 by threading, welding, friction fit or other suitable technique. Slidably positioned within cylinder 230 is a radially telescoping piston 232. Attached to the outer surface of each piston 232 is a longitudinally extending perforated tubular member 234. Disposed within tubular member 234 is a screening element 236 such as prepacked or resin coated sand, metallic or ceramic balls or beads that may be sintered or unsintered or the like. Radially extendable filter members 228 include a pair of fluid flow control devices 238. As this embodiment does not include a swellable material layer, pressure within internal flow path 224 of sand control screen assembly 220 is preferably used to shift radially extendable filter members 228 from their running position to their operating position, as best seen in
While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.
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